CN214227974U

CN214227974U - External rotor adopting punching sheet magnetic conduction block

Info

Publication number: CN214227974U
Application number: CN202120171071.3U
Authority: CN
Inventors: 温群峰
Original assignee: Suzhou Shengyi Motor Co ltd
Current assignee: Suzhou Shengyi Motor Co ltd
Priority date: 2021-01-21
Filing date: 2021-01-21
Publication date: 2021-09-17
Anticipated expiration: 2031-01-21

Abstract

The utility model discloses an external rotor adopting punching magnetic conduction blocks, which comprises a shell, a magnetic conduction frame, magnetic steel and a pressing plate, wherein the shell comprises an end cover and a positioning ring formed on one surface of the end cover, the magnetic conduction frame is positioned on the inner periphery of the positioning ring, the magnetic conduction frame is formed by arranging a plurality of independent magnetic conduction blocks along the circumference, and the magnetic steel is embedded between the adjacent magnetic conduction blocks; the pressure plate is fixed with the end cover by adopting a plurality of axial fasteners so as to press the magnetic conduction frame on the end cover; the magnetic conduction block is characterized in that the magnetic conduction block is a stamped sheet magnetic conduction block formed by laminating stamped sheets, convex step portions are arranged at the front end and the rear end of the magnetic conduction block and are respectively in interference press fit with the concave step portions arranged on the pressing plate and the end cover, so that the magnetic conduction block radially extrudes the positioning ring, and a plurality of radial convex teeth are formed on the interference fit surface of the convex step portions. The outer rotor ensures higher salient pole rate, is more convenient to produce and manufacture, is particularly convenient for the press fit between the magnetic conduction block and the pressing plate and between the magnetic conduction block and the end cover, reduces the manufacturing difficulty, and has good positioning stability for the magnetic conduction block.

Description

External rotor adopting punching sheet magnetic conduction block

Technical Field

The utility model belongs to the technical field of permanent magnet external rotor electric machine's structure, concretely relates to adopt towards external rotor of piece magnetic conduction piece.

Background

The known external rotor motor is widely applied to the field of manufacturing and manufacturing hub motors of electric bicycles, scooters, flatbeds and driving motors of electric automobiles, and is developing towards the technical improvement of low speed and large torque force. The key of the external rotor motor for realizing low speed and large torque force is to improve the salient pole rate of the rotor so as to enable the motor to apply weak magnetic speed regulation and driving technology.

As is known, in the manufacturing of the conventional rotor, the rotor magnetic steel is usually attached to the inner periphery of the annular iron core, which has the disadvantage of low salient pole ratio, and is not beneficial to applying technologies such as field weakening speed regulation driving and the like on the outer rotor motor, so that the performance of the low-speed high-torque motor cannot be better improved. As an improvement, the existing rotors, particularly the inner rotor of an inner rotor motor, are provided with magnetic conductive supports which are formed by laminating punching sheets and are sleeved on the periphery of a rotor core, and magnetic steel grooves which are radially extended and used for embedding magnetic steel are arranged on the magnetic conductive supports at intervals along the circumference, so that each magnetic steel is installed along the radial direction of the rotor core, the magnetic steel arrangement on the circumference is more, the salient pole rate is effectively improved, the application of the technologies of weak magnetic speed regulation driving and the like on the motors is facilitated, and the low-speed large torque is better realized.

However, the outer rotor is different from the inner rotor, the specification of the outer rotor is larger, if the punching sheet magnetic conduction frame is adopted, the processing difficulty is very high, and the production cost is greatly increased. Meanwhile, the outer rotor adopts the shell to replace a middle rotor iron core as a supporting structure, so that the supporting stability of the magnetic conduction frame is weak. If the diameter of the punching type magnetic conduction frame is designed to be larger, the stability can be further reduced, and the positioning stability of the magnetic steel fixed on the punching type magnetic conduction frame is further influenced.

The rotor with the structure can ensure that the motor has higher salient pole rate, but after practical application, the magnetic conduction frame is found to be slightly insufficient in magnetic flux performance, and is not as good as the magnetic conduction frame laminated by the original punching sheet.

As an improvement, if the magnetic conduction block manufactured by laminating and pressing punching sheets is designed to replace the original magnetic conduction block of powder metallurgy, a better effect can be obtained, convex step parts are designed at the bottoms of the front end and the rear end of the magnetic conduction block, and meanwhile, concave step parts are arranged on the pressing plate and the end cover of the rotor shell and are respectively in interference press fit with the convex step parts on the front end and the rear end of the magnetic conduction block, so that the magnetic conduction block is supported and positioned. When the magnetic conduction block is fixed to the end cover by the fastener, certain radial acting force can be generated due to the interference of the pressing plate, the magnetic conduction block and the matching part of the end cover and the magnetic conduction block, so that the trend that the magnetic conduction block is extruded towards the inner peripheral wall of the positioning ring is formed, the positioning stability of the magnetic conduction block and magnetic steel thereof is improved, and the working reliability of the rotor is enhanced.

However, the following problems still exist in the practical implementation:

1) when the interference fit surfaces on the concave step part and the convex step part are both flat surfaces, the pressing plate and the magnetic conduction block and the end cover of the rotor shell are difficult to press in and assemble.

2) In actual operation, inclined planes can be machined on the matching surfaces of the concave step portion and the convex step portion to facilitate press fit, but the magnetic conduction block formed by lamination of punching sheets is adopted, and the inclined planes are very difficult to machine due to process reasons.

Therefore, a better outer rotor is urgently needed in the industry at present, the production and the manufacture are more convenient while the salient pole rate is higher, the production cost is lower, and the positioning stability of the magnetic steel is better.

Disclosure of Invention

The utility model discloses the purpose is: the outer rotor adopting the stamped magnetic conduction blocks is more convenient to produce and manufacture while ensuring higher salient pole rate, is particularly convenient for press fit between the magnetic conduction blocks and a pressing plate and between the magnetic conduction blocks and an end cover, reduces the manufacturing difficulty, and has good positioning stability for the magnetic conduction blocks.

The technical scheme of the utility model is that: an outer rotor adopting punching magnetic conduction blocks comprises a shell, a magnetic conduction frame, magnetic steel and a pressing plate, wherein the shell comprises an end cover and a positioning ring formed on one surface of the end cover, the magnetic conduction frame is positioned on the inner periphery of the positioning ring, the magnetic conduction frame is formed by arranging a plurality of independent magnetic conduction blocks along the circumference, and the magnetic steel is embedded between every two adjacent magnetic conduction blocks; the pressure plate is fixed with the end cover by adopting a plurality of axial fasteners so as to press the magnetic conduction frame on the end cover; the magnetic conduction block is characterized in that the magnetic conduction block is a stamped sheet magnetic conduction block formed by laminating stamped sheets, convex step parts are arranged at the front end and the rear end of the magnetic conduction block and are respectively in interference press fit with concave step parts arranged on the pressing plate and the end cover, and radial force pointing to the direction of the positioning ring is applied to the convex step parts by the concave step parts so that the magnetic conduction block radially extrudes the positioning ring; and a plurality of radial convex teeth are formed on the interference matching surface of the convex step part.

Further, in the present invention, the radial teeth are evenly spaced on the interference fit surface along the circumferential direction of the outer rotor. For example, connected in a structure such as a corrugated shape or a saw-tooth shape.

Further, every in the utility model the left and right sides of magnetic conduction piece all is equipped with magnet steel half draw-in groove, and two magnet steel half draw-in grooves relative on two adjacent magnetic conduction pieces on the circumference are pieced together the magnet steel draw-in groove and are adorned the magnet steel in order radially to inlay.

Further, in the utility model discloses in half draw-in groove of magnet steel is L shape draw-in groove, pieces together the radial width of magnet steel draw-in groove all is greater than its circumference width, just the top of magnet steel offsets with the interior week wall of position circle.

Furthermore, in the present invention, the top surface of the magnetic conductive block is a cambered surface that is attached to the inner peripheral wall surface of the positioning ring.

The utility model discloses when implementing, in order to strengthen every magnetic conduction piece's location steadiness for cross-under stationary platen's axial fastener also can cross-under stationary magnetic conduction piece simultaneously. For example, each magnetic conductive block is fastened to the end cover by the axial fasteners in a penetrating manner, that is, the axial fasteners and the magnetic conductive blocks are arranged in a one-to-one corresponding relationship. Or one part of the magnetic conduction block is fastened to the end cover by the axial fastener in a penetrating way.

Furthermore, in the present invention, the number of the part of the magnetic conductive blocks accounts for 1/3-1/2 of the total number of the magnetic conductive blocks.

Further, in the present invention, the axial fastening member is a screw, a bolt or a rivet.

The utility model has the advantages that:

1. the utility model discloses an external rotor, its magnetic conduction piece that constitutes magnetic conduction frame is folded by the punching and is pressed and form, compares original powder metallurgy cast magnetic conduction piece, has not only ensured to have improved the salient rate, makes the magnetic conduction frame also have the advantage in the aspect of the magnetic conductivity moreover to the wholeness ability of the motor of using this kind of external rotor has further been improved.

Therefore, the utility model discloses ensure equally that the motor that adopts this external rotor can use weak magnetism speed governing and drive technique, the big torsion of better realization low-speed, motor torsion can improve more than 50% under same input power to ensure that what this type of motor can be better is used on electric bicycle, scooter, flatbed and electric automobile.

2. In the further design of the utility model, the front and the rear ends of the magnetic conductive block are provided with the convex step parts which are respectively in interference press fit with the concave step parts arranged on the pressing plate and the end cover, thereby supporting and positioning the magnetic conductive block by means of the pressing plate and the end cover, and greatly improving the positioning stability of the magnetic conductive block; and when the magnetic conduction block is locked to the end cover by the axial fastener, the matching position of the convex step part and the concave step part can generate certain interference magnitude due to stress, so that certain radial acting force is formed, the magnetic conduction block is extruded to the inner peripheral wall of the positioning ring all the time, the radial inward collapse of the magnetic conduction block in long-term use is prevented, the magnetic conduction block is further reinforced, the positioning stability of the magnetic steel is ensured, and the working reliability of the whole outer rotor is enhanced.

3. The utility model provides a further shaping has a plurality of radial dogtooths on the interference fit surface of the convex step portion of its preceding, rear end of magnetic conduction piece, and pressure when this kind of structure can increase the extrusion to the corresponding concave step portion that is favorable to clamp plate and end cover is with the mode and the magnetic conduction piece extrusion assembly of interference, also is favorable to the magnetic conduction piece to be extruded with the mode of interference and fixes a position on the inner perisporium of position circle.

4. The utility model discloses when guaranteeing that motor salient pole rate improves, its magnetic conduction frame is arranged by a plurality of solitary towards piece magnetic conduction piece along the circumference and constitutes, and non-whole by the punching pile, just so makes the production and processing of magnetic conduction frame become simple, and the cost also reduces, really makes this kind of external rotor can be produced and implemented and be used for on the big torsion external rotor electric machine of low-speed, and then improves the motor performance.

Drawings

The invention will be further described with reference to the following drawings and examples:

FIG. 1 is a cross-sectional view of the front structure of an embodiment of the present invention (with the platen removed);

FIG. 2 is a cross-sectional view taken along line A-A of the embodiment of FIG. 1;

fig. 3 is an enlarged view of a portion B in fig. 2 (showing an interference press-fit enlarged structure of the front and rear ends of the magnetic block and the pressure plate and the end cap, and an axial fixing structure of the magnetic block).

Wherein: 1. a housing; 101. an end cap; 102. positioning rings; 2. magnetic steel; 3. a magnetic conduction block; 301. a magnetic steel half clamping groove; 4. pressing a plate; 5. an axial fastener; 6. a convex step portion; 7. a recessed portion; 8. a radial lobe; C. interference fit surface.

Detailed Description

Example 1: combine fig. 1~3 to show, for the utility model relates to an adopt concrete implementation of towards piece magnetic conduction piece's external rotor, it comprises shell 1, magnetic conduction frame, a plurality of magnet steel 2 and clamp plate 4 jointly, the utility model discloses well shell 1 comprises end cover 101 and the position circle 102 of shaping in end cover 101 one side jointly. The magnetic conduction frame is located on the inner periphery of the positioning ring 102, and in the embodiment, the magnetic conduction frame is formed by arranging 30 independent magnetic conduction blocks 3 along the circumference, each magnetic conduction block 3 is fixed to the end cover 101 through an axial fastening piece 5, and the axial fastening pieces 5 are screws. In this embodiment, the magnetic conductive blocks 3 are all stamped magnetic conductive blocks formed by laminating stamped sheets. The center of the end cover 101 is provided with a shaft hole, which is used for being sleeved on a motor shaft of the outer rotor motor as in the conventional technology.

As shown in fig. 1, the magnetic steel half slots 301 are disposed on the left and right sides of each magnetic conductive block 3, and two magnetic steel half slots 301 opposite to each other on two adjacent magnetic conductive blocks 3 on the circumference are jointly spliced into a magnetic steel slot to radially embed the magnetic steel 2, as shown in fig. 1. In addition, in this embodiment, the magnetic steel half slot 301 is an L-shaped slot, the radial width of the magnetic steel slot is greater than the circumferential width of the magnetic steel slot, and the top of the magnetic steel 2 abuts against the inner peripheral wall surface of the positioning ring 102.

The pressing plate 4 is used for pressing the magnetic conduction frame on the end cover 101, and the pressing plate 4 is jointly fastened to the end cover 101 by the screws fastened to the magnetic conduction blocks 3 in a penetrating manner, as shown in fig. 2 and 3. In this embodiment, the top surface of the magnetic conductive block 3 is an arc surface attached to the inner peripheral wall surface of the positioning ring 102.

Referring to fig. 1 to 3, in this embodiment, the front end and the rear end of the magnetic block 3 are provided with a raised portion 6, which are respectively press-fitted with a recessed portion 7 provided on the pressing plate 4 and the end cover 101. As can be seen from fig. 1 to 3, the pressing plate 4 and the recessed portion 7 of the end cap 101 are both configured to press the magnetic conductive block 3 toward the inner peripheral wall of the retainer ring 102, so that the force applied to the raised portion 6 by the recessed portion 7 is a radial force toward the retainer ring 102. And four radial convex teeth 8 (only the radial convex tooth 8 at the front end is disclosed in fig. 1) are formed on the interference fit surface C of the convex step portion 6 at the front end or the rear end of the magnetic conduction block 3, and the four radial convex teeth 8 are uniformly distributed on the interference fit surface C at intervals along the circumferential direction of the outer rotor. The structural design can increase the pressure during extrusion, thereby facilitating the extrusion assembly of the pressing plate 4 and the corresponding concave step part 7 of the end cover 101 and the convex step part 6 on the magnetic conduction block 3 in an interference manner, and also facilitating the extrusion positioning of the magnetic conduction block 3 on the inner peripheral wall of the positioning ring 102 in an interference manner.

The above-mentioned embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention, which should not be construed as limiting the scope of the present invention. All modifications made according to the spirit of the main technical scheme of the present invention shall be covered within the protection scope of the present invention.

Claims

1. An outer rotor adopting punching magnetic conduction blocks comprises a shell (1), a magnetic conduction frame, magnetic steel (2) and a pressing plate (4), wherein the shell (1) comprises an end cover (101) and a positioning ring (102) formed on one surface of the end cover (101), the magnetic conduction frame is positioned on the inner periphery of the positioning ring (102), the magnetic conduction frame is formed by arranging a plurality of independent magnetic conduction blocks (3) along the circumference, and the magnetic steel (2) is embedded between every two adjacent magnetic conduction blocks; the pressure plate (4) is fixed with the end cover (101) by adopting a plurality of axial fasteners (5) so as to press the magnetic conduction frame on the end cover (101); the magnetic conduction block is characterized in that the magnetic conduction block (3) is a stamped sheet magnetic conduction block formed by laminating stamped sheets, convex step portions (6) are arranged at the front end and the rear end of the magnetic conduction block (3) and are respectively in interference press fit with concave step portions (7) arranged on the pressing plate (4) and the end cover (101), so that the magnetic conduction block (3) radially extrudes the positioning ring (102), and a plurality of radial convex teeth (8) are formed on an interference fit surface (C) of each convex step portion (6).

2. The external rotor adopting the punching magnetic conduction blocks as claimed in claim 1, wherein the radial convex teeth (8) are uniformly distributed on the interference fit surface (C) at intervals along the circumferential direction of the external rotor.

3. The external rotor adopting the stamped magnetic conducting blocks as claimed in claim 1, wherein magnetic steel half slots (301) are formed in the left side and the right side of each magnetic conducting block (3), and two opposite magnetic steel half slots (301) on two circumferentially adjacent magnetic conducting blocks (3) are jointly spliced into a magnetic steel slot to radially embed the magnetic steel (2).

4. The external rotor adopting the punching magnetic conduction block as claimed in claim 3, wherein the magnetic steel half clamping groove (301) is an L-shaped clamping groove, the radial width of the spliced magnetic steel clamping groove is larger than the circumferential width of the spliced magnetic steel clamping groove, and the top of the magnetic steel (2) is abutted against the inner circumferential wall surface of the positioning ring (102).

5. The external rotor adopting the punching magnetic conduction blocks as claimed in claim 1, wherein the top surface of the magnetic conduction block (3) is an arc surface attached to the inner peripheral wall surface of the positioning ring (102).

6. The external rotor adopting punching magnetic conduction blocks as claimed in claim 1, wherein each magnetic conduction block (3) is cross-connected and locked to the end cover (101) by the axial fastening piece (5), or a part of the magnetic conduction blocks (3) is cross-connected and locked to the end cover (101) by the axial fastening piece (5).

7. The external rotor adopting the stamped magnetic conduction blocks as claimed in claim 6, wherein the number of the magnetic conduction blocks (3) is 1/3-1/2 of the total number of the magnetic conduction blocks (3).

8. The external rotor adopting the punching magnetic conduction blocks as claimed in claim 1, wherein the axial fasteners (5) are screws, bolts or rivets.